Vintage Synth Repair

From: David Scarponi
Subject: Re: [vintagesynthrepair] Yamaha AN1X - one key has always max velocity
To: vintagesynthrepair@yahoogroups.com
Received: Sunday, 2 August, 2009, 10:23 PM

I had a Kurzweil SP-76 with the same problem. A friend fixed it by removing a piece of dirt that was inside the keyboard.

--- On Fri, 7/31/09, Daniel Forro wrote:

From: Daniel Forro
Subject: Re: [vintagesynthrepair ] Yamaha AN1X - one key has always max velocity
To: vintagesynthrepair@ yahoogroups. com
Date: Friday, July 31, 2009, 8:22 PM

In my opinion this can be caused by some dirtiness, dust or so, on
PCB under the rubber switch. These switches are in stripes which can
be easily removed to clean the PCB with isopropylalcohol. If the
switch is broken, then key wouldn't play.

In these rubber switches usually there are two contacts, one is
shorter, so it will make contact later.

So definitely I would buy it, repair is easy if you have some
experience with it. That virtual analog synth has a lot of nice
features, I liked it a lot when I had it.

Better keyboards with metal contact usually measure time between
disconnecting one contact (starting position) and connecting the
other one. It's more simple method mechanically - only one switch.

Best regards

Daniel Forro

On 1 Aug 2009, at 9:42 AM, alan_probandt wrote:

> There's a Yamaha AN1X keyboard on eBay which the seller claims has
> one key that always plays at max velocity regardless of how hard or
> soft it is pressed. Does anyone have any thoughts about what could
> be causing this and what could fix it?
> As I understand, velocity on a keyboard is measured by having two
> switches. One activates at the beginning of the keypress and the
> other activates at the completion of the keypress. The velocity
> value is based on the time between the two switch activations. If
> the bottom switch were broken to be never activated, it would
> appear that the player is taking infinite time to depress the note,
> and, I would guess, the velocity would be zero for this key. It
> would never sound.
> If the bottom switch were always activated, pressing the key
> would appear to have zero time between the top switch activating
> and the bottom switch activating, giving instant keypress and max
> velocity.
>
> The Yamaha AN1X is a MIDI based late 1990s Analog Synth
> Modeller. The opening bid is $200. Does this seem like a
> reasonable buy according to the collective wisdom here?
>
> Thank you.